Date   
Re: Homebrew from scratch #ubitx

Richie Chambless
 

Hello Woolf,

I have Eagle layout files for the RF sections of the UbitX. I took a modular approach, so there are several circuit boards that you could make a UbitX or a single conversion design. I've been thinking about uploading them to the files section for some time but I just haven't done it. Here are a couple of pictures of the exciter section (single conversion). Let me know if you would like them and I get email them to you:

Re: Homebrew from scratch #ubitx

Mike aka KC2WVB <rb5363@...>
 

You could ask Mike Hagen, WA6ISP, if he would share his design/... for his modified Raduino. Its structure is probably the easiest part of your planned endeavor.

On Jun 17, 2018 4:56 PM, "Woolf Brebner" <woolfoftheworld@...> wrote:
I'd like to build a uBitx completely from scratch. I've been looking at the circuit diagram and I cant figure out how to wire up the raduino. How would one make a raduino from scratch and wire it to a uBitx? I'd preferably like to be able to build it on a proto board. Would it be doable for someone with pretty good experience in wiring pcbs and proto-boards to build a uBitx from scratch on a proto board. If not does anyone have pcb designs for the uBitx and the raduino. And does anyone have a list of everything I would need to purchase to build a uBitx. I don't want to ask to much but if anyone has built a uBitx from scratch and has files and such that would be great. Thanks a lot, in advance.


Re: Nextion Displays >> warning

Nick VK4PP
 

Hi All, 
SO what happens if you have a TJC screen? Hoping they are not useless now...
73 NIck

Re: Raduino needed.

Mike aka KC2WVB <rb5363@...>
 

Mike Hagen, WA6ISP, is selling an "improved" Raduino for roughly $48. It is completely assembled for that price. If you Google his name and call sign you should get an email address for him or just browse the UBitX help blog until you see his name show itself.


On Sun, Jun 17, 2018, 2:42 PM Dennis Yancey <bigbluedry@...> wrote:
Looking for a factory Raduino. Hoping someone has one they aren’t using. If not, can someone tell me how to get one from the factory?  LCD is not necessary. 

Thanks
72 and God bless.

Re: Nextion Displays >> warning

Nick VK4PP
 

Re: Anyone ever use one of these to build a Raduino clone?

Nick VK4PP
 

Low RX Audio #ubitx

El Calvo
 

Hi!!! 

My ubitx rx audio level on 80m and 40m bands is good, but 20m and above is very low. I verified my antena with other radios and is working fine. Even the tx on 20m up to 10m is up to spec, but the receive audio is vey weak.  Any ideas where to check??? Thanks and 73 de WP3DN

Re: Anyone ever use one of these to build a Raduino clone?

MVS Sarma
 

once one could design his own board , perhaps integrating the si chip also on board  simplifies things. While saying so,  I assume, that si chips lives long enough.

rtegards
sarma
 vu3zmv


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 9:09 AM, Nick VK4PLN <nickpullen@...> wrote:
Hi Dennis, Yes, see here: https://vk4pln.blogspot.com/2018/03/vk4pln-ubitx-add-on-boards.html

Cheers.


Re: Low RX Audio #ubitx

MVS Sarma
 

Do you use Farhan's ubitx v3 board or made one for yourself?


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 9:28 AM, <3voltios@...> wrote:
Hi!!! 

My ubitx rx audio level on 80m and 40m bands is good, but 20m and above is very low. I verified my antena with other radios and is working fine. Even the tx on 20m up to 10m is up to spec, but the receive audio is vey weak.  Any ideas where to check??? Thanks and 73 de WP3DN


Re: Nextion Displays >> warning

Mike Woods
 

I have it on good advice (from Ian) that you will be able to use a 2.4 or 2.8 TJC version with a pre-compile from KD8CEC!

Mike ZL1AXG

On Mon, 18 Jun 2018 at 3:09 PM, Nick VK4PLN <nickpullen@...> wrote:
Looks like there is a way to use the TJC with the NXT firmwares... :

https://translate.google.com.au/translate?hl=en&sl=ru&u=http://robotclass.ru/tutorials/arduino-nextion-tjc/&prev=search

73.

Re: Nextion Displays >> warning

Nick VK4PP
 

Excellent, so just put the .tft file on an sd card, inseart, upload and done. That would be GREAT!

Thanks Ian!

73 Nick VK4PLN

Re: Low RX Audio #ubitx

iz oos
 

In TX how much power do you get?


Il 18/giu/2018 06:51, "Mvs Sarma" <mvssarma@...> ha scritto:
Do you use Farhan's ubitx v3 board or made one for yourself?


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 9:28 AM, <3voltios@...> wrote:
Hi!!! 

My ubitx rx audio level on 80m and 40m bands is good, but 20m and above is very low. I verified my antena with other radios and is working fine. Even the tx on 20m up to 10m is up to spec, but the receive audio is vey weak.  Any ideas where to check??? Thanks and 73 de WP3DN



Re: Low RX Audio #ubitx

MVS Sarma
 

iz oos,
The Tx power and Rx sensitivity are different issues, I suppose.
at times if we carefully tweak the coils(LPF before 1st mixer) , in effect slight changes in their inductance vales, we can perhaps improve on sensitivity. This action  could be either increase , or decrease slightly. One has to be cautious while doing not to break the coils at the soldering point.


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 11:34 AM, iz oos <and2oosiz2@...> wrote:

In TX how much power do you get?


Il 18/giu/2018 06:51, "Mvs Sarma" <mvssarma@...> ha scritto:
Do you use Farhan's ubitx v3 board or made one for yourself?


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 9:28 AM, <3voltios@...> wrote:
Hi!!! 

My ubitx rx audio level on 80m and 40m bands is good, but 20m and above is very low. I verified my antena with other radios and is working fine. Even the tx on 20m up to 10m is up to spec, but the receive audio is vey weak.  Any ideas where to check??? Thanks and 73 de WP3DN




Re: Low RX Audio #ubitx

iz oos
 

Most of circuitry is used for both TX and RX, so that is why I asked for TX power output. If TX works, than I would look to those parts not used on TX. Maybe there is some switch (diode or relay) that does not work properly. Maybe in this case kits like signal tracer by Hendricks may be useful to detect the defective part, solder joint, if any.


Il 18/giu/2018 08:29, "Mvs Sarma" <mvssarma@...> ha scritto:
iz oos,
The Tx power and Rx sensitivity are different issues, I suppose.
at times if we carefully tweak the coils(LPF before 1st mixer) , in effect slight changes in their inductance vales, we can perhaps improve on sensitivity. This action  could be either increase , or decrease slightly. One has to be cautious while doing not to break the coils at the soldering point.


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 11:34 AM, iz oos <and2oosiz2@...> wrote:

In TX how much power do you get?


Il 18/giu/2018 06:51, "Mvs Sarma" <mvssarma@...> ha scritto:
Do you use Farhan's ubitx v3 board or made one for yourself?


Regards
MVS Sarma
 

On Mon, Jun 18, 2018 at 9:28 AM, <3voltios@...> wrote:
Hi!!! 

My ubitx rx audio level on 80m and 40m bands is good, but 20m and above is very low. I verified my antena with other radios and is working fine. Even the tx on 20m up to 10m is up to spec, but the receive audio is vey weak.  Any ideas where to check??? Thanks and 73 de WP3DN




Re: Arduino needed.

Mike aka KC2WVB <rb5363@...>
 


Mike Hagen, WA6ISP, is selling an "improved" Raduino for roughly $48. It is completely assembled for that price. If you Google his name and call sign you should get an email address for him or just browse the UBitX help blog until you see his name show itself.


On Sun, Jun 17, 2018, 2:39 PM Dennis Yancey <bigbluedry@...> wrote:
I am looking for a factory Arduino. Would like to find someone that has one they aren’t using. Or, how can I order one from the factory? LCD is not necessary.

Thanks,

72 and God bless.

Re: The BITeensio board is here. #ubitx

David Wilcox
 

I saw one like it at Dayton and almost sprung for it.  Looked neat but was a little on the flimsy side.  But it looked functional.

Dave K8WPE

On Jun 17, 2018, at 9:31 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:

Has anyone tried this type of scope:

<s-l1600.jpg>
(eBay 352344602558)? For $60, I'd be very interested if it works.

Jack, W8TEE

On Sunday, June 17, 2018, 1:16:28 AM EDT, Kevin Luxford <kbgluxford@...> wrote:


To my dear XYL's chagrin, I have just purchased a stereo AmScope SE400-X
microscope with fixed 5x or 10x magnifications (depending upon the
eyepice selected).  This has a 9 inch distance to the work object and a
wide field of view, so very little chance of burning one's nose with the
soldering iron. But USD200! + freight down here to Oz.  However it
provides a stereo view of the pcb with great clarity.  I understand that
freight to CONUS is free. Usual disclaimers.

73 all,
Kevin VK3DAP  / ZL2DAP





<s-l1600.jpg>

Ubitx V4 opinions?

M0CLS
 

Hi all.

I’m about to buy another ubitx, but I’m a little concerned about one or 2 of the posts concerning the audio of this latest board.

Has anyone with the V4 experienced any distorted audio or any other related issues? I’m hoping this was an isolated case and not an issue with the audio circuit on these new boards.... 

Regards
Carl M0CLS

Re: uBitx V4 linearity mod in final audio amplifier #ubitx

Weddig, Henning-Christof <Henning-Christof.Weddig@...>
 

Mike and all UBITX enthusiasts,
when In looked on the schematic of the new audio amp my first thougt was: why is there no feedback from the output to the input?
Please have a look on the very old schenatics of "old" and discrete audio amps and even tube amps!!!
In all circuitries a feedback is installed to cancel the nonlinearities of the active elements.

Henning Weddig
DK5LV

Am 17.06.2018 um 23:23 schrieb Mike:

I believe there is an nonlinearity problem on some of the newer V4 uBitx radios (the one with transistors in the final audio amp). Two of my radios had this problem.
The problem is that the two diodes in the final amp doesn't make a voltage drop that is larger than the drop over the BJT B-C junction drops, so there will be a crossover distortion problem.
I did a mod: cut the trace between the diodes. Soldere in a 500 ohm pot paralelled with the a 125 ohm resistor. I adjusted the pot from a low value and increased the resistance until the nonlinearity disappeared by listening to a moderately strong cw signal. I checked the lower transistor so it didnt become too warn from the quiescent current.
73s

Re: Homebrew from scratch #ubitx

Frank Dinger , EI7KS
 

Hi Richie, tnx for the pics re your ubitx modular approach . This is  homebrewing in the true sense.
Tnx for sharing .

73  Frank    EI / GM0CSZ    and KN6WH

Re: Ubitx V4 opinions?

Gordon Gibby
 

Well there actually is some feedback, it is in the form of those emitter resistors in the final audio amplifier. R75 R77

The crossover distortion may be that in order to properly bias those transistors “on”, just a bit of emitter current has to flow, creating a voltage drop across those two emitter  resistors (e.g. choose 10mA * 4.4 ohms=44mV), which is not accounted for by the Voltage drops across the diode’s on their base side.

Current through R75 should be about 0.6 mA.
Suggests added series R = 44mV/0.6mA= 75 ohms

Gordon (back of the envelope calculation’s)

image1.png


On Jun 18, 2018, at 06:11, jocarl011 <jocarl011@...> wrote:

Hi all.

I’m about to buy another ubitx, but I’m a little concerned about one or 2 of the posts concerning the audio of this latest board.

Has anyone with the V4 experienced any distorted audio or any other related issues? I’m hoping this was an isolated case and not an issue with the audio circuit on these new boards.... 

Regards
Carl M0CLS